By Nick Johnson
In November 2020, Carla Reid and her daughter, Hannah, were out walking on one of the parcels of land owned by the Reid family on Cayman Brac.
Both Carla and her daughter are keen naturalists. In fact, Hannah Reid writes a very informative blog about the traditional environmental knowledge of Caymanian people; ‘BushGirlMedicine’. Carla Reid is credited with the rediscovery of Salvia caymanensis, once thought to be extinct in the wild on Grand Cayman.
Both knew that the small tree they found that day on their walk was special, something neither had seen before. It had yellow flowers, fine leathery leaflets and tiny black spines on the new growth. But what was it?
Photos were taken and Hannah collected a sample to bring home to see if she could work out its identification. They sent as much information as they could to me at the QEII Botanic Park and together we started to try to identify it.
While out driving round the island looking for other examples of this small tree, Carla and Hannah spotted another unusual, multi-stemmed, spiny shrub.
This plant was also new to the family, so documentation began on this too. After a few days of searching and running through identification keys for plants in the Cayman Islands, it dawned on me that while we had managed to get the plants identified down to the sub-family level, we could go no further with the books of the flora of the Cayman Islands. Could these be un-documented species?
I sent the pictures and information that I had to Dr. Martin Hamilton and Professor Colin Clubbe at the Royal Botanic Gardens, Kew. Both are old colleagues from my time at Kew and Martin heads up the UK Overseas Territories unit in the Herbarium there.
The two experienced botanists began their work, keying out the species to literature focused on the wider Caribbean flora.
Meanwhile, I decided to do a deep dive into identifying the two species myself using online tools.
The second multi-stemmed shrub was the only one I had success with. After identifying it as a Caesalpinia, I decided to go through every single Caribbean species and rule each one out. This genus is huge, having over 70 species listed, including the beautiful national flower of Barbados, Caesalpinia pulcherrima.
Fortunately, very few have a flower like the one found in Cayman Brac, so I managed to whittle it down to five species. Eventually, after much deliberation I settled on Caesalpinia bahamensis. This species had previously been recorded in the Bahamas, Cuba and Hispaniola according to ‘Plants of the World Online’.
Sadly Colin, Martin, Hannah and I had no luck identifying the small tree with yellow flowers, so the decision was taken to call in the big gun – specialist in Leguminosae trees, Dr Gwilym Lewis. Gwil has worked in Kew’s herbarium for decades and has written several publications on neo-tropical Caesalpinia trees. He almost immediately identified our mystery yellow flowered tree as Tara vesicaria. Another species that is native to Cuba and Hispaniola but has also been recorded on mainland Central America. In fact, when looking at a map of the countries it has been recorded in, one could almost predict that it should occur here!
Now that we had some identifications to go by, Carla, Hannah and I decided to officially record these species as native plants to the Brac.
With advice from Dr Gwil and Professor Colin, we set about collecting as much representative data as we could. We enlisted another keen naturalist to our cause, Mr. Frank Roulstone to take photographs with his amazing camera equipment. For both species we collected three herbarium samples; these are dried pressings that botanists use to formally identify plants. Two of those herbarium samples will be lodged with the National Herbarium of the Cayman Islands, currently residing at the Department of Environment. One sample will be lodged with Kew, where it will go into a library of samples of plants taken from all over the British Overseas Territories. These specimens are digitized, the resulting high-resolution photographs are posted online for everybody to access.
We also collected DNA samples. These samples will be sent to Kew, where they have the largest plant DNA database in the world, allowing scientists to compare and analyse the data found within. This can help them discover new medicines, understand plant relationships and even discover how long a species has been on an island!
Samples of the flowers were also taken and put into a ‘spirit collection’. This will help botanists to see the flower in three dimensions, not just flattened on an herbarium sheet. We also collected seed samples and wood samples, ensuring the records for these two species were comprehensive.
After visiting and documenting both species, Frank took us to Peter’s Cave to show us a tree that George Proctor had identified as a Cassia. Frank had assisted Dr. Procter on his many visits while he was writing his book ‘The Flora of the Cayman Islands’. It turns out that Proctor’s Cassia was in-fact our mystery tree too, Tara vesicaria! According to Frank, when Dr. Proctor saw it, he dismissed it as a garden escapee and decided not to include it in his magnum opus for the Cayman Islands.
Finding and documenting these species is important work, if we do not know and understand our natural habitats, we could be missing pieces of the puzzle if we ever have a need to restore them. Also, to quote Dr. Gwil: “Proctor’s 1990’s suggestion that the tree is a Cassia escaped from cultivation just shows how interesting species can be dismissed/remain undiscovered for decades due to misidentification.”
One of the many reasons that the Queen Elizabeth II Botanic Park was founded was to enable the people of the Cayman Islands to come closer to their floral heritage and to represent that diversity to the next generation through school tours. Visitors will soon be able to see the new additions to our flora, seeds of both species germinated in our nursery and are being grown for planting out in our gardens.
Our thanks go to the people of Cayman Brac for making us feel very welcome and hydrated during the dry season!